Universal attachment drive unit for automatic screw machine

ABSTRACT

An auxiliary drive unit which consists of a cylindrical housing which has an extension arm attached thereto for the support of an idler shaft; the cylindrical housing is mounted in a bore of a wall of the gear box of the automatic screw machine and the extension arm is disposed within the housing; a shaft extends through the housing and into the gear box and has a gear mounted adjacent the extension arm to mesh with a gear on the idler shaft which is supported in the extension arm of the housing; a further gear is mounted on the idler shaft within the gear box housing which is adapted to mesh with a gear supported and driven by the main spindle drive shaft of the automatic screw machine. The gears on both the housing shaft and idler shaft can be easily interchanged to obtain different auxiliary drive arrangements and drive ratios for different purposes. Conversely, the driving connection from the idler shaft of the auxiliary drive unit to the housing shaft of the drive unit can be provided for by a chain drive.

United States Patent Eichenhofer 15 3,657,939 1451 Apr. 25, 1972 [54] UNIVERSAL ATTACHMENT DRIVE UNIT FOR AUTOMATIC SCREW MACHINE Josef Eichenhofer, 120 Oakdale Road,

[72] Inventor:

Downsview 479, Brampton, Ontario, Canada [22] Filed: Aug.5, 1970 [21] Appl.No.: 61,261

Primary Examiner-Robert M. Walker A rr0rney--Cullen, Settle, Sloman & Cantor 57] ABSTRACT An auxiliary drive unit which consists of a cylindrical housing which hasan extension arm attached thereto for the support of an idler shaft; the cylindrical housing is mounted in a bore of a wall of the gear box of the automatic screw machine and the extension arm is disposed within the housing; a shaft extends through the housing and into the gear box and has a gear mounted adjacent the extension arm to mesh with a gear on the idler shaft whichis supported in the extension arm of the housing; a further gear is mounted on the idler shaft within the gear box housing which is adapted to mesh with a gear supported and driven by the main spindle drive shaft of the automatic screw machine. The gears on both the housing shaft and idler shaft can be easily interchanged to obtain different auxiliary drive arrangements and drive ratios for different purposes. Conversely, the driving connection from the idler shaft of the auxiliary drive unit to the housing shaft of the drive unit can be provided for by a chain drive.

21 Claims, 12 Drawing Figures PATENTEDAPR 25 I972 SHEET 2 BF 4 FIG? uwemm JOSEF sacm-muorsa G M M fla @fiz ATTORNEYS PATENTEB APR 2 5 I972 SHEET L UF 4 mvsmon JOSEF EICHENHOFER ATTORNEYS I 1 unrve'nsxr. ATTACHMENT DRIVE UNIT FOR AUTOMATIC SCREW MACHINE BACKGROUND OF THE INVENTION v 2 SUMMARY or THE INVENTION The present invention relates to auxiliary attachment drive units for a machine tool and more in particular to an attachment drive unit for a multi-spindle automatic screw machineadapted to perform a variety of functions in a conveniently adjustable manner. i

Some of these functions are as follows: (1) the attachment drive spindle shaft can be synchronized for speed and direction of rotation in accordance with the speed and direction of rotation of the work spindles of the automatic screw machine; (2) the spindle shaft of the improved attachment drive unit can be made to be rotated in opposite direction to the rotation of the main spindle drive shaft respecformed on a workpiece by the indexed spindles of the machine. These auxiliary spindles are often required to be synchronized with the speed and direction of rotation of the work spindles driven at varying speeds by the main spindle drive shaft and in other instances are required to run in reverse or the same direction but at different speeds than that of thework spindles. 1

Usually all tool spindles are driven from one central main spindle drive shaft through change speed Jgea'rs. The main spindle isusually driven'from a gear box'comprising aplurality of change gears staged at'various ratios relative to each other. The drive power is taken from a selected pair of change gears in accordance with the speed of revolution required for the particular machining operation. Consequently, the gears engaged withthe auxiliary spindle destined to drive various auxiliary tools can'be used for only one machining operation at a time. Thesame applies to auxiliary high speed drilling drives having an intermediate gear and a setof change speed gears.

The primary object of the present invention is to simplify the auxiliary drive arrangement for rotary tools utilized in I multi-spindle automatic screw machines or lathes.

These units must be able tobe used in any machining position and they receive their driving power usually from the main transmission gear box of the multi-spindle automatic screw machine.

As presently known, each of these auxiliary attachments has its own special drive, which is connected to the main transmission of the automatic screw machine. These independent spe cial drives cannot easilybe interchanged from one position to another position, that is, from performing one machining operation to performing another machining operation. Additionally, prior to the present invention, changing of the driving ratio ordirection of rotation of the auxiliary attachment spindle in relation to the main spindle drive shaft and work spindle of the automatic screw machine was difficult to accomplish.

Conventionally, in presently known auxiliary attachment drive units, in order to have a variety of speed changes, it was required to have a complete set of change speed gears to be interchangeably secured to the drive shaft or take-offshaft'of the conventional attachment drive unit. This obviously requires keeping a large number of gears in stock and additiohal man hours, i.e., time and expense, in the initial set up'of the screw machine. 1

Typical multi-spindlescrew machines or lathes usually consist of a gear box mounted opposite to the head stock which provides a support for the indexing spindle carrier and the differential cross slide. Located between the gear box and the oppo'site head stock is the tooling area where the actual machining takes place. The attachment drive unit is also located in the tooling area andextends into the gear box and is supported by the gearbox housing. The change speed gears for the attachment drive unit, which may either be spur gears, helical gears, or chain drives, are for the most part located inside the gear box of the automatic screw machine for driving connection with the main spindle drive shaft, at the same time supply ing afixed relationship relative to the main spindle drive shaft.

tively. The work spindles of the automatic screw machine may have a speed ratio different from the speed ratio set by the main spindle drive shaft of the'automatic screw machine which can beaccomplished by interchanging just one gear in the attachment drive unit; (3) the spindle shaft of the improved attachment drive unitcan be made to be rotated in the same direction as the main spindle drive shaft of the automatic screw machine having a variety of speed ratios which is accomplished by interchanging just one gear in the attachment drive unit. v

Most of the presently known attachment drive units for machine tools, and particularly automatic screw machines, are mounted for extension and support through bothvfront and rear walls of the gear box of the machine tool in alignment with the spindle center. The drive mechanisms for theauxiliary attachment drive spindles, which have been used in the past, were usually particularly designed and built for a specific purpose and specific work operation to be performed by the attachment drive unit. In most prior known instances, due to the particular construction the attachment drive unit could not be interchanged between different screw machine spindle positions and, as mentioned before, they needed a large number of speed changing gears required for different machining purposes and therefore were costly to produce and required excessive man hours for initial set up of the machine.

present improved attachment drive unit is mounted only in the front wall of the gear box of the automatic screw-machine and is driven from the main spindle drive shaft of the automatic screw machine by a single gear only.

More in particular, the present improved attachment drive unit itself consists of a drive sleeve which by means of ball bearings is supported in the cylindrical attachment drive housing.

Driven by a gear, drive-connected with the main spindle drive shaft of the machine, the motion is transferred via change gears and intermediate drive gears to the drive sleeve. An idler shaft is mounted in an arm extension of the housing in such fashion that it can swivel around the axis of the housing which is mountedin the attachmentbore in the front wall of the gear box of the automatic screw machine. The attachment drive unit housing itself is clamped in the bore bymeans of a wedge arrangement, which provides a secure and simple locking means when changing to a different speed ratio by means of changing the change gear. The front end of the attachment drive shaft is constructed in such a way that different adapter bushings can be mounted thereon to comply with different attachment spindle drive shaft arrangements in accordance with the respective attachment being used.

By using the intermediate drive gears, the attachment spindle will be driven in opposite direction to that of the main spindle drive shaft with the drive ratio being set by the respec: tive change gear. A plurality of different speeds can be obtained.

The intermediate drive gears can be interchanged with a chain drive which then will rotate the attachment spindle in the same direction as the main spindle drive shaft. In this arrangement, likewise, the drive ratio is set by the change gear with a plurality of different speeds being available.

In a third arrangement, the complete idler shaft'can be taken off and an intermediate drive gear will be positioned to directly mesh with the main spindle drive shaft gear. This arrangement also provides rotation of the attachment spindle in the same direction as that of the main spindle and at the same RPM.

More in particular, the front wall of the gear box of the automatic screw machine has an upright inner face which is apertured and which is adapted to receive the present novel universal attachment drive unit. The unit is bolted in place and projects into the gear box and is mounted thereto by means of y a mounting flange, which bears against the gear box wall or,

alternatively, fastened thereto by means of a wedging arrangement. Thus, most of the assembly at the left side of the mounting flange of the unit will be inside of the gear box.

The present improved universal attachment drive unit includes a cylindrical housing which projects through the gear box wall.

The housing is provided with a longitudinal bore supporting a pair of ball bearings at opposite ends which are suitably secured in place, and which are adapted to rotatably support the attachment drive shaft.

The housing at one end, within the gear box, has a reduced diameter portion which terminates into an arm extension which is integral with or suitably fastened to the housing.

The arm extension is provided with a bore to receive a ball bearing or the like adapted to rotatably support the attachment drive shaft which extends through the housing. The bore in the arm extension includes thrust bearings or washers at opposite ends in order to hold the attachment drive shaft against longitudinal displacement.

The attachment drive shaft is of a tubular construction and at one end, the attachment drive shaft is provided with internal splines for direct drive or to receive an internally splined coupling sleeve. The coupling sleeve can be replaced by other coupling sleeves having different internal splines or notches and being of different internal diameters to accommodate various attachment drive spindles. The front end of the attachment drive shaft is also adapted to receive different attachment gears of different pitch diameters.

On the other end of the attachment drive shaft and on the other side of the arm extension a spur gear is mounted. An external spacer which is serrated or otherwise internally splined is positioned short of the end of the attachment drive shaft which projects through the gear box wall. The attachment drive shaft is threaded at the end to receive a lock nut, the nut being slotted externally to receive one of the projections of a lock ring for anchoring the nut to the attachment drive shaft once it has been rethreaded in retaining engagement with the external spacer.

The arm extension is provided with an idler shaft which carries the change gear and one of the intermediate gears. The change gear is adapted for meshing engagement with the takeoff gear on the main spindle drive shaft and the intermediate gear is in mesh with the gear on the attachment drive shaft to transfer rotatably driving power from the main spindle drive shaft to the attachment spindle.

BRIEF DESCRIPTION OF THE DRAWINGS The appended drawings illustrate various preferred embodiments of the present improved universal, auxiliary attachment drive unit in which:

FIG. 1 is a schematic assembly illustration showing the present improved attachment drive unit mounted in an automatic multi-spindle screw machine;

FIG. 2 shows one embodiment of the present improved attachment drive unit mounted in the wall of the gear box of an automatic screw machine;

FIG. 3 is a front view of the unit shown in FIG. 2 taken in the direction of arrows 33;

FIG. 4 to 8 schematically illustrate various possible drive arrangements of the present improved attachment drive unit which will be described in detail in the specification;

FIG. 9 illustrates a further preferred embodiment of the present improved attachment drive unit;

FIG. 10 is a longitudinal cross-section through the improved attachment drive unit of FIG. 9;

FIG. 11 is a perspective illustration of the improved attachment drive unit of FIG. 9; and

F IG. 12 illustrates a further modification of the present improved attachment drive unit embodying a chain drive mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now to FIG. 1 of the drawings there is illustrated, schematically, a machine tool 10, such as a multi-spindle automatic screw machine. The automatic screw machine 10 is provided with a main spindle drive shaft 12 which is adapted to drive a plurality of work spindles of which only two are indicated at 14 and 16, and which are normally disposed in the head stock of the automatic screw machine.

The main spindle drive shaft 12 is driven by means of a motor 18 disposed on the machine 10. The speed and rotation of the main'spindle drive shaft 12 is usually variable by means of a plurality of gearing arrangements (not shown) located in the gear box 20 of the automatic screw machine.

Located adjacent and parallel with the main spindle drive shaft 12 is an auxiliary spindle drive shaft 22 usually provided on such type of machines to provide for various auxiliary machining functions in addition to the work operations provided for by the machine spindles 14 and 16. The auxiliary spindle drive shaft 22 is driven by means of an auxiliary attachment drive unit 24 which is mounted such as to extend into the gear box 20. The auxiliary attachment drive unit 24 is adapted to be driven by means of a gear 25 mounted on the main spindle drive shaft 12 within the gear box 20,

Referring now to FIGS. 2 and 3, the improved auxiliary attachment drive unit 24 of the present invention is comprised in general of a cylindrical housing 26 which is stationarily mounted in the bore 28 of the gear box housing wall 21. The cylindrical housing 26 supports an attachment drive shaft 30 which at the outer end, that is outside of the gear box 20, is drivingly connected to the auxiliary spindle drive shaft 22 for rotation of the latter.

Integral with or mounted on the housing 26 is a bearing support 32 in the form of an arm which is disposed inside of the gear box 20 adjacent the wall 21. The bearing support 32 is adapted to support an idler shaft 34 at the end opposite from the shaft 30. The shaft 30 and the idler shaft 34 are adapted to be provided selectively with a variety of gears for purposes to be explained in the following.

In FIG. 2 the idler shaft 34, on the upper end of the arm 32, receives a speed change gear 36 which is adapted to mesh with the main spindle drive shaft gear 25 to transfer driving torque to the auxiliary attachment drive unit from the main spindle drive shaft 12. A transfer gear 38 is interposed between change speed gear 36 and the arm 32 on the idler shaft 34 for meshing engagement with attachment drive gear 40 which is secured to the attachment drive shaft30 between the bearing support 32 and a synchronizing sleeve 42 which is disposed around the shaft 30 for a purpose to be explained later on.

A detailed description of the preferred structure of the present improved auxiliary attachment drive unit will be given later on in the description in connection with the description ofFIGS. 9 and 10.

The attachment drive unit when arranged in the manner shown in FIG. 2 and 4 is in a position for high speed drilling operations through the auxiliary spindle drive shaft 22. The auxiliary spindle drive shaft 22 will be driven in the same direction as the direction of rotation of the main spindle drive shaft 12 by means of the transfer gear 38 and gear 40.

disposed around the inner end of the In t the driving arrangement of the improved attachment driveunit schematically illustrated in F 10.5, the transfer gear 38 and attachment drive gear 40 have been replacedby a chain drive indicated at 44. This arrangement causes the spindle drive shaft-'22 to be rotated in the opposite direction as the main spindle drive shaft 12 by meansof the chain drive 44 and is used for plain threading operations on a work piece through rotation of the auxiliary spindle drive shaft 22 FIGS. 1, 2.

In the arrangement in FIG. '6, a pick-off gear 46 has been addedto the end of the attachment drive shaft 30.

V The 'pick-off'gear 46, shown in FIG. 6, is adapted for pickoff of stock material and the drive is preferably synchronized with the drive of the main spindle drive shaft or .work spindles .of' the automatic screw machine. Synchronization is accomplished by means of the slip coupling arrangement 42, attachment drive shaft 30 and which will 'be described 'in detail further on in the a description.

The arrangement in FIG. 7 illustrates schematically adif- 'ferentpurpose driving arrangement, which may be either gear driven as in FIG. 4, chaindriven as in FIG. 5, or pick-off driven asin FIGJ6 so the the drive'can be selectively in the same direction of rotation as the main spindle drive shaft, in opposite direction, orsynchronized therewith. This arrangement is used for any kind of attachment adapted formilling, slotting, burnishing, stenciling, etc.

I In the arrangement of the present'improved universal at tachmentdrive unit, shown in FIG. 8, a frontdrivegear 48 is attachedtothe attachment drive shaft 30 adjacent the cylindricalhousing 26 and outwardly ofthe gear box '20. The front drive .gear 48 isadapted to mesh with an idler gear 50, as indicated in FIG. 1, which is disposed for rotation outwardly of the front wallgear box 20. Thus, by this arrangement, the present improved attachment drive unit is adaptable for other workpositions and functions within the machine in addition to the provision of the driving the attachment drive spindle 22.

With reference now to FIGS. 9 and 10, there is illustrated more in'detail a preferred construction of the .presentimproved attachment drive unit 24.

The attachment drive unit 24, as shown in FIG.9 and 10, is comprised of a cylindrical housing 26, which is disposed within thebore 28 of the front wall 21 of the gear box 20.

In this preferred embodiment, the'cylindrical housing 26 whichcarries the drive unit 24, is retained within thebore 28 of the gear box front wall 21 by a-unique Wedge and split sleeve locking arrangement,generally indicated at 54 in FIG.

1 9. As'seen in FIG. 9 and 10, a portion of the cylindrical housing wall-is cut out as at 56, to receive oppositely disposed split sleeve sections 58 and 60 which are independently movable radially relative to the solid remainder of the housing. The oppositeendsofthe cutout 56 expand intoaxial slots 62 to permit radial outward extension of the split sleevegsections 58 and 60. The inner opposed faces 59 and 61 of the split sleeve sections 58 and 60 are oppositely inclined and are adapted to be engaged by a wedge member 64 disposed between the split sleeve sections 58and 60 for axial movement therebetween. To permit axial movement of the wedge member 64 in the releasing direction of the wedge lock, the cylindrical housing Wallis provided with a=recess 66 opposite the end of the wedge member 64 which intersects the cut out 56. As more clearly shown in FIG. 10, the rear end of the wedge member 64 is provided with an upstanding flange portion 68 which, in assembly, is adapted to abutagainst the inner surface of the side wall2l of the gear box 20. The wedge flange. 68 is provided with a threaded aperture 70 adapted to receive the threaded shank 72 of a lock screw 74. The head portion of the lock screw'74 isretainediagainst axial movement within a rectangular, outwardly open recess 76 provided in the end of a radial extension 78 of the housing 26. The radial extension 78 is slotted axially as seen at 80which extends, towards the wedge member 64, into an enlarged portion 82 to permit axial movement of the wedge member 64 in the opposite, locking direction. Thus, by rotation of the lock screw 74, in one I flange type extension arm 32 direction, the wedge member64, since the lock screw 74 is retained against axial movement, will be moved towards the recess 66 in unlocking position, and by opposite direction of rotation of the'lock screw 74, the wedge member 64 will be moved into the recess 82 into locking position.

The split sleeve sections 58 and 60 normally form a smooth cylindrical continuation with the cylindrical outer surface of the housing 26. After the housing 26 has been inserted into the bore 28, the lock screw 74 is rotated in a direction to move the wedge member 64 rearwardly, that is, into the recess 82 of the housing extension 78. Due to the inclined surfaces 59 and 61 of the split sleeve I sections 58 and 60, which match the inclined surfaces of the wedge member 64, the split sleeve sections 58 and 60 are thereby displaced radially outwardly into the slots 62 and into tight frictional contact against the internal surface of the bore 28, to thereby rigidly lock the housing 26 within the bore 28 in any desirable rotatably adjusted posi tion. In order to unlock the housing 26 from the bore 28, the lock screw 74 is rotated in opposite direction thereby moving the wedge member 64 axially into the recess 66, causing the wedge expansion force on the split sleeve sections 58 and 60 to be relieved, to release the frictional contact between the split sleeve sections 58 and 60 and the internal surface of the bore 28.

The cylindrical housing 26 is provided integrally with a which is an opposite continuation of the extended portion 78 of the housing.

The upper end of the extension arm 32 is apertured, as at 84, to receive an idler shaft 34 which, at one end, has an integral head portion 88 adapted for seating engagement within a counter bore 90 coaxial with the bore 84 on one side of the extension arm 32.

The idler shaft 34 extends outwardly from the upper end of the extensionarm 32 and is threaded at its end to receive a lock nut 92 and thrust washer 94. A sleeve bushing 96 is nonrotatably mounted on the idler shaft 34 between the thrust washer 94 and innerside of the extension arm 32. The sleeve bushing 96 has a radialflange97 at its inner end, towards the extension arm '32, which is adapted to be retained within a counter bore 100 atthe opposite side of the extension arm 32, similar to and coaxially aligned with the counter bore90 and the aperture 84. Thus, when the lock nut 92 is tightened, the sleeve bushing 96 is securely clamped axially between the thrust washer 94 and the inner lateral side of the counter bore 100 in the extension arm 32.

The sleeve bushing 96 supports a pair of spaced needle bearings 98 to rotatably mount the intermediate transfer gear 38. The transfer gear 38 has an extended hub portion 102 which is adapted to selectively mount the driven input gear 36 which is destined tobe in mesh with the drive gear 25 disposed on the main spindle drive shaft 12 (see FIG. 1). To absorb axial thrust loads, a thrust washer 104 is disposed between the inner end of the gear 38 and the radial flange 97 of the sleeve bushing 96.

The cylindrical housing portion 26 is provided with an axial bore 106 which, at the outer end, terminates into an enlarged counter bore 108 adapted to receive a pair of anti-friction bearings 110.

The inner end of the bore 106 of the cylindrical housing 26, within the extension arm 32, is similarly provided with a counter-bore 11 2'to likewise receive a pair of anti-friction bearings l 14.

The spaced pairs of anti-frictionbearings 110 and 114 are adapted to rotatably support the attachment drive shaft 30, which extends through the bore l06 in the cylindrical housing 26 for extension inwardly of the gear box 20 and outwardly beyond the side wall 21. The drive shaft 30 is preferably of tubular construction for light weight and is adapted to normally support the attachment spindle drive gear 40, non-rotatably secured thereto by means of a key 116. In assembly, the hub of the attachment spindle drive gear 40, which-is disposed adjacent the inner side of the extension arm 32, abuts against the confined between the gear 40 and the inner radial face of the counter bore 112 and are additionally confined in axial direction against a radial flange 31 extending circumferentially from the outer surface of the attachment drive shaft 30.

Normally, the attachment spindle drive gear 40 is axially confined between the bearings 114 and the slip coupling 42 disposed at the inner end of the attachment drive shaft 30, which in assembly is axially retained by means of a lock nut 118 disposed on the threaded inner end of the attachment drive shaft 30. Preferably, a lock washer 120 is disposed between the lock nut and the slip coupling42.

The slip coupling assembly 42 is comprised of an axially toothed outer ring 41, an axially toothed intermediate ring 43-which is provided with axial teeth at both ends-and an axially toothed inner ring 45 which is integral with the respective gear selectively placed on this end of the attachment drive I shaft 30. The slip coupling assembly 42 is retained against rotation on the attachmentdrive shaft 30 by means of the same key 116 which secures the respective gear to the shaft. The slip coupling assembly 42 is provided to be operable whenever synchronization of the rotatable speed between the main spindle drive shaft 12 and the attachment spindle drive shaft 22 is desired.

The outer end of the attachment drive shaft 30'is internally splined, as at 33, for rotatably driving connection with the attachment spindle drive shaft 22 as seen in FIG.-2. The outer end of the attachment drive shaft 30 is adapted to selectively mount a transfer gear 48 which may be secured thereto by means of a key 122. A spacer 124 is provided between the pair of bearings 110 and the inner face of the gear 48 to maintain the gear 48 in spaced relation relative to the end of the tubular housing 26. The gear 48 is axially confined against the spacer 124 by means of a lock nut 126 disposed at the threaded outer end of the attachment drive shaft 30. v

The lock nut 126, at the outer end of the attachment drive shaft 30, is provided with an inner radial circumferentially ex tending recess 128 forming a radial flange 130 at the outer end of the lock nut 126.

This arrangement of the lock nut 126, at the outer end of the attachment drive shaft 30, is provided to clampingly mount an adapter sleeve, indicated at 132, which is externally provided with radial lugs 134 adapted to fit into the internal radial recess 128 of the lock nut'l26 for driving engagement with axial lugs 135 provided at the end of drive shaft 30 so that, when the lock nut 126 is tightened against the gear 48, the radial lugs 134 of the adapter sleeve 132 will be axially floating between the outer end of the attachment drive shaft 30 and the flange 130 of the lock nut 126 to provide a floating locking arrangement for the adapter sleeve. By this arrangement, selected adapter sleeves having various internal diameters may be securely attached to the end of the attachment drive shaft 30 for rotation therewith to accommodate various sizes of attachment spindle drive shafts. It will be understood that the internal diameter of the adapter sleeve 132 is provided with serrations or splines for secure, non-rotatable attachment of the respective attachment spindle drive shaft.

It should be mentioned here that FIG. 9 is an end-to-end inverted view of the improved auxiliary attachment drive unit in respect to the assembly cross-section shown in FIG. 10.

An alternate gear arrangement is indicated in dot-and-dash lines at the bottom of FIG. at the inner end of the attachment drive shaft 30. In this arrangement, a pick-off gear 46, such as shown schematically in FIG. 6, is mounted at the extreme end of the attachment drive shaft 30 and the slip coupling assembly 42 is reversed in position for disposal between the pick-off gear 46 and the bearing assembly 114. Thus, the outer ring 41 of the slip coupling assembly 42 is now at the inside and the inner ring 45, which is integral with the pick-off gear 46, is disposed at the outside. As mentioned previously, particularly when using the pick-off gear 46, synchronization of the attachment drive mechanism with the main spindle drive is required, which is provided for by the slip coupling assembly 42.

The preferred construction of the improved auxiliary attachment drive unit just described in connection with FIG. 9 and 10, is shown in perspective view in FIG. 11 in which the identical parts are indicated by the same reference numerals and which needs no further explanation.

Referring to the perspective illustration of the alternate drive arrangement of the improved attachment drive unit shown in FIG. 12, which is identical with the arrangement shown schematically in FIG. 5, the transfer gear 38 and at-.

tachment spindle drive gear 40 are herein replaced by a chain drive mechanism 44 which provides for rotation of the attachment spindle drive shaft in the same direction as that of the main spindle drive shaft 12.

It will be obvious from the foregoing description in conjunction with the appended'drawings, that the present invention provides an improved universal, auxiliary attachment drive unit for a multi-spindle machine tool, which is compact in arrangement and construction and requires only a minimum number number of parts to be' interchanged from one work position requirement to another. I

The present universal attachment drive unit is mounted only in the front wall of the gear box of the multi-spindle machine tool, thereby considerably facilitating assembly and disassembly of the unit.

The present improved universal attachment drive unit is adapted to provide different ratios between the main spindle drive shaft and the attachment spindle drive shaft simply be changing only'one gear. The direction of rotation can be changed by replacing the gear drive with a chain drive.

By changing the drive gear to a different location on the drive sleeve or attachment drive shaft, the attachment spindle drive shaft can be driven in synchronism with the main spindle drive shaft.

A particular unique feature is provided by the novel wedge action clamping means of the improved attachment drive unit to lock the unit within the bore of the gear box wall, which is provided for by a wedge disposed between split sleeve sections of the unit housing to be expanded into locking engagement within the bore by means of a stationary lock screw which moves the wedge.

Although the present invention has been described in connection with a preferred embodiment, it will be obvious to those skilled in the art to which the invention pertains that various changes in construction and arrangement may be made without departing from the spirit and essential characteristic of the invention as defined by the scope of the appended claims.

Iclaim:

1. In combination with a machine tool having a main spindle drive shaft and a gear box; a universal attachment drive unit adapted to drive supplementary tools independent from the tools driven by said main spindle drive shaft, the improvement comprising: a cylindrical housing stationarily mounted in the being-provided with a transversely extending arm portion disposed within said gear box; means mounting a first gear on said shaft adjacent said arm; means mounting a second gear on the end of said arm adapted for meshing engagement with said first gear; a third gear mounted on said arm adjacent said second gear and in co-acting relationship thereto; said main spindle drive shaft being provided with a take-off gear adapted to mesh with said third gearto thereby transfer rotatable driving force from said drive shaft to said attachment drive shaft; means disposed between said first gear and said attachment drive shaft in co-acting relationship therewith to cause synchronization between said main spindle drive shaft and 3. In the combination as defined in claim 1, including further means on the outer end of said attachment drive shaft for selectively mounting a fifth gear; said fifth gear being adapted for meshing engagement with an idler gear disposed on the wall of said gear box to transfer portions of the drivingpower through said attachment drive unit to within saidmachine.

4. In the combination as defined in claim 1, the means for mounting the second gear comprising an idler shaft stationarily secured at one end within the upper portion of said arm and extending outwardly therefrom; said second gear being rotatably supportedon said idler shaft.

5. In the combination as defined in claim 4, said second gear being provided with an axial hub extension adapted for mounting said third gear for non-rotatablesecurement thereto so as to co-jointly rotate with said second gear.

6. In the combination as defined in claim 1, said other positions synchronization means comprising a slip coupling keyed to said attachment drive shaft; said slip coupling comprising a sleeve member, an intermediate ring member and an end ring member integral with or attached to the respective gear disposed on said attachment drive shaft; said sleeve member and said intermediate ring member being connected by intermeshing circumferentially extending axial teeth and said intermediate ring member and said end ring member similarly connected by circumferentially extending axial teeth to permit limited radial movement between said members upon application of driving torque by said gear disposed on the attachment drive shaft.

7. In the combination as defined in claim 1, said universal attachment drive unit being mounted for sole support in one wall of said gear box only, the main portion of said universal attachment drive unit extending within said gear box freely supported in cantilever fashion on said attachment drive shaft.

8. In the combination as defined in claim 1, said third gear being a change speed gear adapted to be interchanged with other gears to change the speed ratio between the main spindle drive shaft and said attachment drive shaft and said first and second gears are transfer gears which cause rotation of said attachment spindle shaft in a direction the same as the direction of rotation of said main spindle drive shaft.

9. In the combination as defined in claim 8, said first and second gear comprising sprockets and a drive chain'trained around said sprockets adapted, upon driving rotation by said third gear, to cause said attachment spindle shaft to be rotated in the opposite direction of rotation as said main spindle drive shaft.

10. In the combination as defined in claim 1, the further provision of means to lock said housing in the bore of said gear box wall against rotation relative thereto; said means comprising: a split sleeve forming part of said housing adapted for expandable movement against the interior of said bore into frictional engagement therewith, a wedge slidingly disposed between the opposite portions of said split sleeve; means adjustably moving said wedge in axial direction for selective expansion or contraction of said split sleeve portions to thereby selectively unlock said housing for quick removal from said bore or securely lock said housing in said bore in a selected rotatably adjusted position of said attachment drive unit.

11. In the combination as defined in claim 10, said means to axially move said wedge member between the opposite portions of said split sleeve comprising: a flange extending up wardly from said wedge member and a lock screw threadedly engaged within said flange; said lock screw having a head portion confined within a recess provided in a radial flange exten sion of said housing to prevent axial movement of said lock screw upon rotation thereof to thereby axially displace said wedge member to change the radial position of said split sleeve-portions relative to said housing. I

12..A universal attachment drive unit for a machine tool or the like adapted to be drivingly connected to the main spindle drive shaft of said machine tool; said unit comprising: a cylindrical housing; a hollow shaft rotatably supported within said housing for extension outwardly at both ends of said housing; said shaft being adapted to selectively mount a first rotatable driving member at one end thereof outwardly of said housing and to selectively mount a second rotatable driving member at the other end of said shaft outwardly of said housing; said housing being provided with an extension arm at one end thereof extending in a direction transverse to the longitudinal direction of said shaft; means at the outer end of said extensionarm to selectively mount a third rotatable driving member in co-planar alignment with and drivingly engaging said second rotatable driving member on said shaft; said third rotatable driving member having means to mount a fourth rotatable driving member in co-acting relationship and for conjoint rotation therewith; said main spindle drive shaft having means to drivingly engage said fourth rotatable driving member so that upon rotation of said main spindle drive shaft said fourth rotatable driving member will be rotated to thereby rotate said third rotatable driving member which in turn rotates said second rotatable driving member on said shaft to rotate said shaft in a direction the same as the direction of rotation of said main spindle drive shaft, and interchangeable means at the outer end of said shaft adjacent said first gear to selectively mount an attachment spindle shaft in co-axial alignment with said shaft and to be driven thereby.

13. In the attachment drive unit as defined in claim12, said fourth rotatable driving member being a change speed gear provided to vary the speed of rotation between said shaft and said main spindle drive shaft.

14. In the attachment drive unit as defined in claim 12, said second and third rotatable driving member being spur gears in meshing engagement with each other and having a fixed ratio adapted to transfer driving power from said main spindle drive shaft through said speed changing gear to said shaft.

15. In the attachment drive unit as defined in claim 12, said second and third rotatable driving member being sprockets and a drive chain being trained around said sprockets to drivingly connect said sprockets and rotate said sprockets in the same direction of rotation upon application of driving power to said change speed gear.

16. In the attachment drive unit as defined in claim 12, said means at the outer end of said extension arm comprising an idler shaft secured within said arm against rotation and extending therefrom in a direction parallel to the directionof said shaft for mounting said third and fourth rotatable driving members.

17. In the attachment drive unit as defined in claim 12, further providing means at one end of said shaft adjacent said second rotatable driving member adapted for synchronization between said main spindle drive shaft and said shaft of said attachment drive unit. t

18. In the attachment drive unit as defined in claim 17, said means for synchronization comprising: a slip coupling keyed to said shaft comprised of a plurality of members connected together for limited radial and axial movement relative to each other, one of said members being connected to said second rotatable driving member, and a nut member threadedly engaging the end of said shaft to confine said shaft.

19. In the attachment drive unit as defined in claim 18, the further provision of reversing the position of said slip coupling on said shaft when said second rotatable driving member is removed from said shaft and attaching a fifth rotatable driving member to said shaft in a clamped position between said nut member and said reversed slip coupling; said one member of said slip coupling being connected to said fifth rotatable member. v

20. In the attachment drive unit as defined in claim 12, said attachment shaft having means at the outer end of said shaft adjacent said first rotatable driving member to accommodate said slip coupling on the mounting of an attachment spindlewdrive shaft thereto in 1 coaxial alignment with said attachment shaft; said means comprising a selectively variable coupling sleeve disposed on the outer end of said shaft and a nut member threadingly engaging said shaft for securing said coupling sleeve to said shaft.

upon tightening of said nut member on said shaft said lugs of said coupling sleeve will be retained in floating engagement against the end of said shaft by said nut member to thereby floatingly retain said coupling sleeve on said shaft. 

1. In combination with a machine tool having a main spindle drive shaft and a gear box; a universal attachment drive unit adapted to drive supplementary tools independent from the tools driven by said main spindle drive shaft, the improvement comprising: a cylindrical housing stationarily mounted in the wall of said gear box; anti-friction bearing means within said housing for rotatable support of an attachment drive shaft extending therethrough and into said gear box; said housing being provided with a transversely extending arm portion disposed within said gear box; means mounting a first gear on said shaft adjacent said arm; means mounting a second gear on the end of said arm adapted for meshing engagement with said first gear; a third gear mounted on said arm adjacent said second gear and in co-acting relationship thereto; said main spindle drive shaft being provided with a take-off gear adapted to mesh with said third gear to thereby transfer rotatable driving force from said drive shaft to said attachment drive shaft; means disposed between said first gear and said attachment drive shaft in coacting relationship therewith to cause synchronization between said main spindle drive shaft and said attachment drive shaft; and means at the outer end of said attachment drive shaft to selectively mount an attachment spindle shaft for rotation therewith.
 2. In the combination as defined in claim 1, means provided on the attachment drive shaft to mount a fourth gear at the end of said shaft adjacent of said synchronization means.
 3. In the combination as defined in claim 1, including further means on the outer end of said attachment drive shaft for selectively mounting a fifth gear; said fifth gear being adapted for meshing engagement with an idler gear disposed on the wall of said gear box to transfer portions of the driving power through said attachment drive unit to other positions within said machine.
 4. In the combination as defined in claim 1, the means for mounting the second gear comprising an idler shaft stationarily secured at one end within the upper portion of said arm and extending outwardly therefrom; said second gear being rotatably supported on said idler shaft.
 5. In the combination as defined in claim 4, said second gear being provided with an axial hub extension adapted for mounting said third gear for non-rotatable securement thereto so as to co-jointly rotate with said second gear.
 6. In the combination as defined in claim 1, said synchronization means comprising a slip coupling keyed to said attachment drive shaft; said slip coupling comprising a sleeve member, an intermediate ring member and an end ring member integral with or attached to the respective gear disposed on said attachment drive shaft; said sleeve member and said intermediate ring member being connected by intermeshing circumferentially extending axial teeth and said intermediate ring member and said end ring member similarly connected by circumferentially extending axial teeth to permit limited radial movement between said members upon application of driving torque by said gear disposed on the attachment drive shaft.
 7. In the combination as defined in claim 1, said universal attachment drive unit being mounted for sole support in one wall of said gear box only, the main portion of said universal attachment drive unit extending within said gear box freely supported in cantilever fashion on said attachment drive shaft.
 8. In the combination as defined in claim 1, said third gear being a change speed gear adapted to be interchanged with other gears to change the speed ratio between the main spindle drive shaft and said attachment drive shaft and said first and second gears are transfer gears which cause rotation of said attachment spindle shaft in a direction the same as the direction of rotation of said main spindle drive shaft.
 9. In the combination as defined in claim 8, said first and second gear comprising sprockets and a drive chain trained around said sprockets adapted, upon driving rotation by said third gear, to cause said attachment spindle shaft to be rotated in the opposite direction of rotation as said main spindle drive shaft.
 10. In the combination as defined in claim 1, the further provision of means to lock said housing in the bore of said gear box wall against rotation relative thereto; said means comprising: a split sleeve forming part of said housing adapted for expandable movement against the interior of said bore into frictional engagement therewith, a wedge slidingly disposed between the opposite portions of said split sleeve; means adjustably moving said wedge in axial direction for selective expansion or contraction of said split sleeve portions to thereby selectively unlock said housing for quick removal from said bore or securely lock said housing in said bore in a selected rotatably adjusted position of said attachment drive unit.
 11. In the combination as defined in claim 10, said means to axially move said wedge member between the opposite portions of said split sleeve comprising: a flange extending upwardly from said wedge member and a lock screw threadedly engaged within said flange; said lock screw having a head portion confined within a recess provided in a radial flange extension of said housing to prevent axial movement of said lock screw upon rotation thereof to thereby axially displace said wedge member to change the radial position of said split sleeve portions relative to said housing.
 12. A universal attachment drive unit for a machine tool or the like adapted to be drivingly connected to the main spindle drive shaft of said machine tool; said unit comprising: a cylindrical housing; a hollow shaft rotatably supported within said housing for extension outwardly at both ends of said housing; said shaft being adapted to selectively mount a first rotatable driving member at one end thereof outwardly of said housing and to selectively mount a second rotatable driving member at the other end of said shaft outwardly of said housing; said housing being provided with an extension arm at one end thereof extending in a direction transverse to the longitudinal direction of said shaft; means at the outer end of said extension arm to selectively mount a third rotatable driving member in co-planar alignment with and drivingly engaging said second rotatable driving member on said shaft; said third rotatable driving member having means to mount a fourth rotatable driving member in co-acting relationship and for conjoint rotation therewith; said main spindle drive shaft having means to drivingly engage said fourth rotatable driving member so that upon rotation of said main spindle drive shaft said fourth rotatable driving member will be rotated to thereby rotate said third rotatable driving member which in turn rotates said second rotatable driving member on said shaft to rotate said shaft in a direction the same as the direction of rotation of said main spindle Drive shaft, and interchangeable means at the outer end of said shaft adjacent said first gear to selectively mount an attachment spindle shaft in co-axial alignment with said shaft and to be driven thereby.
 13. In the attachment drive unit as defined in claim 12, said fourth rotatable driving member being a change speed gear provided to vary the speed of rotation between said shaft and said main spindle drive shaft.
 14. In the attachment drive unit as defined in claim 12, said second and third rotatable driving member being spur gears in meshing engagement with each other and having a fixed ratio adapted to transfer driving power from said main spindle drive shaft through said speed changing gear to said shaft.
 15. In the attachment drive unit as defined in claim 12, said second and third rotatable driving member being sprockets and a drive chain being trained around said sprockets to drivingly connect said sprockets and rotate said sprockets in the same direction of rotation upon application of driving power to said change speed gear.
 16. In the attachment drive unit as defined in claim 12, said means at the outer end of said extension arm comprising an idler shaft secured within said arm against rotation and extending therefrom in a direction parallel to the direction of said shaft for mounting said third and fourth rotatable driving members.
 17. In the attachment drive unit as defined in claim 12, further providing means at one end of said shaft adjacent said second rotatable driving member adapted for synchronization between said main spindle drive shaft and said shaft of said attachment drive unit.
 18. In the attachment drive unit as defined in claim 17, said means for synchronization comprising: a slip coupling keyed to said shaft comprised of a plurality of members connected together for limited radial and axial movement relative to each other, one of said members being connected to said second rotatable driving member, and a nut member threadedly engaging the end of said shaft to confine said slip coupling on said shaft.
 19. In the attachment drive unit as defined in claim 18, the further provision of reversing the position of said slip coupling on said shaft when said second rotatable driving member is removed from said shaft and attaching a fifth rotatable driving member to said shaft in a clamped position between said nut member and said reversed slip coupling; said one member of said slip coupling being connected to said fifth rotatable member.
 20. In the attachment drive unit as defined in claim 12, said attachment shaft having means at the outer end of said shaft adjacent said first rotatable driving member to accommodate the mounting of an attachment spindle drive shaft thereto in coaxial alignment with said attachment shaft; said means comprising a selectively variable coupling sleeve disposed on the outer end of said shaft and a nut member threadingly engaging said shaft for securing said coupling sleeve to said shaft.
 21. In the attachment drive unit as defined in claim 20, said nut member being provided with an internal radial groove and said coupling sleeve having radial lugs adapted for extension within said groove and in driving engagement with complementary axial lugs provided on said attachment shaft so that upon tightening of said nut member on said shaft said lugs of said coupling sleeve will be retained in floating engagement against the end of said shaft by said nut member to thereby floatingly retain said coupling sleeve on said shaft. 